Spraying nozzles

ABSTRACT

A spraying nozzle comprises a body formed with an inlet conduit to receive a fluid under pressure, a first circular chamber coaxial to the axis of the body, an outwardly opening cup-shaped second chamber also co-axial to the body and separated from the first chamber by a transverse wall having a central or first orifice, the open outer end of the second chamber forming the second orifice of the nozzle. The connection between the inlet conduit and the first chamber is so arranged that the fluid whirls within the latter and overflows through the first orifice into the second chamber wherein its angular velocity component decreases progressively while its axial velocity component increases. The frustro-conical spray issuing from the second orifice is thus of reduced conicity. The connecting means between the inlet conduit and the first chamber may be formed of a spiral helicoidal or tangential passage. The nozzle may comprise an inner member extending through both chambers and having a peripheral shoulder situated within the second chamber to form a screen above the first orifice. This inner member may terminate in a tip projecting from the nozzle, or it may be provided hollow so as to receive the body of another nozzle.

[54] SPRAYING NOZZLES [76] Inventor: Pierre Georges Vicard, l5 Cours Eugenie, Lyon, France [22] Filed: July 26, 1971 [21] Appl. No.: 165,890

[30] Foreign Application Priority Data Sept. 16, 1970 France ..7034531 May 17, 1971 France ..71 18730 [52] US. Cl. ..239/11, 239/474, 239/476, 239/497 [51] Int. Cl. .;...B05b 17/04 [58] Field of Search ..239/468492, 494-497, 239/1 1 [56] References Cited UNITED STATES PATENTS 553,727 1/1896 Sickle ..239/474 1,216,146 2/1917 Lissauer ..239/474 2,531,789 11/1950 Rowley ..239/476 X 2,017,467 10/1935 Loomis ..239/497 X Primary Examiner-Lloyd L. King Attorney-Arthur E. Dowell, Jr. et al.

y 51 Jan. 2, 1973 [57] ABSTRACT A spraying nozzle comprises a body formed with an inlet conduit to receive a fluid under pressure, a first circular chamber co-axial to the :axis of the body, an

outwardlyopening cup-shaped second chamber also v co-axial to the body and separated from the first chamber by a transverse wall having a central or first orifice, the open outer end of the second chamber forming the second orifice of the nozzle. The connection between the inlet conduit and the first chamber is so arranged that the fluid whirls within the latter and overflows through the first orifice into the second chamber wherein its angular velocity component decreases progressively while its axial velocity component increases. The frustro-conical spray issuing .from the second orifice is thus of reduced conicity.

The connecting means between the inlet conduit and thefirst chamber may be formed of a spiral helicoidal or tangential passage. The nozzle may comprise an inner member extending through both chambers and having a peripheral shoulder situated within the second chamber to form a screen above the first orifice. This inner member may terminate in a tip projecting from the nozzle, or it may be provided hollow so as to receive the body of another nozzle.

9 Claims, 11 Drawing Figures PATENTEDJAN 2197s 3.7%.1 l9

SHEET 1 OF 3 INVENTOR- P/erre GEG QCS VI C wnmgzz PAIENTEDJAM 2mm 3,708,119

SHEET 3 OF 3 SPRAYING NOZZLES This invention relates to spraying nozzles and has for its object to provide such a nozzle which will produce a frustoconical spray having a quite small angle of conicity.

In accordance with the present invention a method for obtaining such a spray consists:

in imparting to the substance to be sprayed a perfect rotational motion about an axis;

in causing the rotating substance to overflow axially through two successive orifices of increasing diameter, concentric to the said axis;

and in guiding the rotating substance between the said orifices by a wall having an arcuate concave longitudinal profile, in such manner that in the vicinity of the first orifice the rotating substance may have a high angular velocity component with a reduced axial velocity component and that in the vicinity of the second orifice the said substance may have a reduced angular velocity. component with a high axial component.

The invention further concerns a spraying nozzle for the carrying into practice of the abovedefined method.

In the annexed drawings:

FIG. 1 is a longitudinal section of a spraying nozzle according to the invention.

FIG. 2 is a transverse section taken through line 11-- II of FIG. 1. In this figure line I-I corresponds to the section of FIG. 1.

FIG. 3 is a longitudinal section taken through line IIIIII of FIG. 1.

FIG. 4 is a view similar to no. 2, but illustrating a modification.

FIG. 5 is a longitudinal section of another embodiment of this invention.

FIG. 6 is a cross-section taken through line VI-VI of FIG. 5.

FIG. 7 is a longitudinal section of a third embodiment of the invention.

FIG. 8 is a cross-section taken through line VIII- VIII (FIG. 7).

FIG. 9 illustrates a fourth embodiment correspondin g to a double nozzle.

FIG. 10 diagrammatically illustrates how a nozzle according to the invention may be used in order to realize an intimate contact between a fluid and a substance issuing from the noule.

FIG. 1 1 shows a modified arrangement.

The spraying nozzle 1 illustrated in FIGS. 1 to 3 comprises a tubular body 2 having an axial inlet bore 2a which opens into a first annular chamber 2b having a circular transverse section (FIG. 2). The upper wall of chamber 2b is formed with a central circular orifice 2c which opens into a second chamber 2d having the shape of an upwardly flaring cup, the lateral wall of this second chamber corresponding in longitudinal section to a concave arc of a circle or other curve. Considering the tangents to the respective ends of this arc on both sides of the nozzle axis, they define a relatively great angle a adjacent to orifice 2c and a much smaller angle B at the upper orifice 2e of chamber 2d, i. e. at the outlet of the nozzle (respectively for a and [3 about 120 to 130 and 4 to 8 in the example illustrated).

The upper end of bore 2a is screw-threaded and it receives the hollow cylindrical base 3a of an inner member 3. This member comprises a tip 3b .which rises through orifice 2c and projects slightly above the transverse edge of orifice 2e. The lower end of this tip, located within chamber 2b, is in the form of a flat horizontal surface spaced from base 3a and connected with the upper wall 3d of this base by a vertical partition 30 which has in cross-section the shape of a spiral (see FIG. 2). The upper wall 3d is formed with an aperture 3e which opens into the central portion of this spiral.

Supposing the substance to be sprayed is a liquid, it flows under pressure through bore 2a, passes through aperture 3e and is compelled to follow a spiral path before reaching the first chamber 2b within which it whirls freely with a high angular velocity. The whirling liquid flows through orifice 2c and enters the second chamber 2d. Owing to the marked conicity (angle a) of the lateral wall of this chamber in the portion thereof adjacent to orifice 2c, the liquid begins to flow on this wall in the form of a thin continuous layer with a low axial velocity component and a high angular velocity component. But as the liquid rises along the wall of chamber 2d the conicity of the wall decreases and therefore the axial velocity component of the liquid flow increases while its angular velocity component decreases. Finally the liquid layer issues from the nozzle (i.e. from the second orifice 2e thereof) in the form of a frusto-conical sheet of fine particles having a quite small angle of conicity. Owing to the low angular velocity component of the liquid flow within chamber 2d inthe vicinity of orifice 2e, the centrifugal acceleration is reduced and therefore the sprayed sheet only widens quite progressively, which is of advantage in the case of an electrostatic filter, for instance, since this sheet of liquid droplets may effectively form a sleeve surrounding an electrode, as this is often desirable. In such a case the tip 3a may attract and retain ions emitted by ionizing substances which may have settled on this electrode (the inner member 3 and the body 2 being of course metallic or at least metallized in such a case).

It may be of advantage to provide on member 3 a circular shoulder 3f of larger diameter than the first orifice 2c, and situated between the latter and the second orifice 2e, this shoulder forming a screen which prevents foreign bodies from falling directly through the first orifice 20 into the first chamber 2b where they would be retained by centrifugal action. Such foreign bodies, as for instance solid particles falling from an electrostatic electrode, are deflected towards the arcuate wall of chamber 2d from which they are expelled by the liquid.

The nozzle described may be used for spraying solid particles in suspension in a liquid or gas. In such a case, and as illustrated in FIG. 4, there may be provided on the periphery of the nozzle body 2 a tangential inlet 2f which opens into the first chamber 2b. This inlet receives a liquid or gas under pressure which promotes rotation of the solid particles within the chamber independently of the action of the spiral-shaped partition 3; the latter may even be replaced by mere vertical stays.

In the embodiment of FIGS. 5 and 6 the nozzle body 2 (made in two pieces screwed into each other) widens immediately above the inlet bore 2a so as to define a portion of relatively large diameter in which is disposed an axial core 2g integrally connected with body 2 by means of radial arms 2h. Core 2g is formed with a flat horizontal upper surface on which is disposed a hub 4 integral with a radially projecting rib 4a which rises helicoidally through somewhat more than 360 about the axis of the nozzle, its outer edge being substantially in contact with the wall of body 2. The inner member 3 has a screw-threaded tail 3g which is passed through hub 4 and is screwed into a corresponding bore of core 2g. As shown rib 4a forms so to speak the lower wall of the first chamber 2b.

The liquid issuing from the inlet bore 2a is compelled to follow the helical path defined by rib 4a and it is therefore given a high velocity angular component before reaching the first chamber 2b. The nozzle of FIGS. 5 and 6 otherwise operates as above explained.

In the embodiment of FIGS. 7 and 8, the body 2 of the nozzle is closed at its lower end by a circular plate 5 which may be secured in position in any appropriate manner, as for instance by screwing, as shown. This plate supports the hub 4 with its helicoidal rib 4a. The inlet of the liquid is here effected by means of a tangential conduit 2i which opens in the vicinity of the lower end of rib 4a and of course in the proper direction (i.e. in such manner that the liquid jet issuing from conduit 21' tends to flow upwardly along rib 4a). The operation of the nozzle is otherwise as in the case of FIGS. 5 and FIG. 9 illustrates a double nozzle which may be considered as formed of two elementary nozzles of the kind of FIGS. 5 and 6. The first or lower elementary nozzle has a body 2 of large diameter, the core 2g thereof being tubular. This core supports the hub 4 with its helicoidal rib 4a and its axial bore is screw-threaded to receive the tail 3g of the corresponding inner member 3. But here this tail is tubular as core 2g itself, while member 3 is itself hollow and supports the body 12 of the second elementary nozzle. The latter comprises a core 12g, a hub 14 integral with a helicoidal rib 14a, an inner member 13 having a tail 13g which is screwed into core 12g, and so on, the arrangement being the same as in FIGS. 5 and 6, with the same references to which has been however added in order to avoid any confusion with the lower elementary nozzle. It is clear that it would be possible to realize in the same manner multiple nozzles comprising more than two elements.

FIG. 10 indicates how a spraying nozzle according to the invention may be disposed within a conduit 6 through which a fluid (such as a gas) flows in order to treat this gas by the substance sprayed by the nozzle or, more generally, to realize an intimate contact between the substance and the gas. The nozzle 1 is disposed axially in such manner as to produce a frusto-conical spray 7 of reduced conicity the axial velocity component of which is opposite to the flowing velocity of the fluid through conduit 6. The relative velocity between the fluid and the substance being sprayed is therefore considerable, which improves the contacting conditions.

It will be noted that in FIG. 10 the spraying nozzle reduces the cross-sectional area available within conduit 6 for passage of the fluid, which may be of interest to increase the velocity thereof. When the nozzle is of relatively small diameter with respect to the conduit, such an increase may conveniently be obtained by forming in the conduit a Venturi-like contraction, as illustrated at 6a in FIG. 1 l.

I claim:

1. A spraying nozzle comprising:

a body having an axis, said body being formed with an inlet conduit to receive a fluid under pressure, with a first circular chamber co-axial to the said axis and having a first transverse wall and a second transverse wall spaced from each other, with a first circular orifice in said second transverse wall coaxially to said axis, with a second chamber also coaxial to said axis and situated on the other side of said second transverse wall with respect to said first chamber, said second chamber being cupshaped and having a first end adjacent said first orifice and a second end spaced from same, and with a second orifice co-axial to said axis at the second end of said second chamber, said second orifice being of larger diameter than said first orifice;

and means connecting said inlet conduit with said first chamber to cause the fluid under pressure from said inlet conduit to whirl within said first chamber wherefrom it flows into said second chamber through said first orifice with a relatively high angular velocity component and a relatively low axial velocity component and thereafter issues from said nozzle through said second orifice with a lower angular velocity component and a higher axial velocity component.

2. In a spraying nozzle as claimed in claim 1, an inner member co-axial to said axis and located within said first chamber, said first orifice, said second chamber and said second orifice; said member terminating in a tip which projects beyond said second orifice.

3. In a spraying nozzle as claimed in claim 2, said inner member including a circular peripheral shoulder substantially co-axial to said axis, situated within said second chamber and having an outer diameter larger than the diameter of said first orifice.

4. In a spraying nozzle as claimed in claim 1, said connecting means comprising a spiral passage disposed co-axially to said first chamber, said spiral passage having an inner end connected with said inlet conduit and an outer end opening into said first chamber.

5. In a spraying nozzle as claimed in claim 1, said inlet conduit being co-axial to said first chamber, and said connecting means being in the form of a helicoidal passage co-axial to said axis, said helicoidal passage having a first end opening in said conduit and a second end opening into said first chamber.

6. In a spraying nozzle as claimed in claim 1, said connecting means being formed of a passage forming the end of said inlet conduit and opening tangentially into said first chamber.

7. In a spraying nozzle as claimed in claim 1, said inlet conduit being substantially co-axial to said axis and said nozzle further comprising an inner member co-axial to said axis and located within said first chamber, said first orifice, said second chamber and said second orifice; said inner member being formed with an axial through bore having a first end communicating with said inlet conduit and a second end arranged to receive the body of a second spraying nozzle disposed co-axially to the body of said first-named nozzle.

8. A method for spraying a substance which consists:

in imparting to said substance a perfect rotational motion about an axis;

in causing the rotating substance to overflow axially through a first orifice concentric to said axis and thereafter through a second orifice also concentric to said axis and of larger diameter than said first orifice;

and in guiding the rotating substance between the said orifices by a wall having a concave longitudinal profile, in such manner that in the vicinity of the first orifice the rotating substance may have a high angular velocity component with a reduced axial velocity component and that in the vicinity of the second orifice the said substance may have a reduced angular velocity component with a high have a relatively high angular velocity component with a relatively reduced axial velocity component and that in the vicinity of said second orifice said substance may have a relatively reduced angular velocity component and a relatively high axial velocity component. 

1. A spraying nozzle comprising: a body having an axis, said body being formed with an inlet conduit to receive a fluid under pressure, with a first circular chamber co-axial to the said axis and having a first transverse wall and a second transverse wall spaced from each other, with a first circular orifice in said second transverse wall co-axially to said axis, with a second chamber also coaxial to said axis and situated on the other side of said second transverse wall with respect to said first chamber, said second chamber being cup-shaped and having a first end adjacent said first orifice and a second end spaced from same, and with a second orifice co-axial to said axis at the second end of said second chamber, said second orifice being of larger diameter than said first orifice; and means connecting said inlet conduit with said first chamber to cause the fluid under pressure from said inlet conduit to whirl within said first chamber wherefrom it flows into said second chamber through said first orifice with a relatively high angular velocity component and a relatively low axial velocity component and thereafter issues from said nozzle through said second orifice with a lower angular velocity component and a higher axial velocity component.
 2. In a spraying nozzle as claimed in claim 1, an inner member co-axial to said axis and located within said first chamber, said first orifice, said second chamber and said second orifice; said member terminating in a tip which projects beyond said second orifice.
 3. In a spraying nozzle as claimed in claim 2, said inner member including a circular peripheral shoulder substantially co-axial to said axis, situated within said second chamber and having an outer diameter larger than the diameter of said first orifice.
 4. In a spraying nozzle as claimed in claim 1, said connecting means comprising a spiral passage disposed co-axially to said first chamber, said spiral passage having an inner end connected with said inlet conduit and an outer end opening into said first chamber.
 5. In a spraying nozzle as claimed in claim 1, said inlet conduit being co-axial to said first chamber, and said connecting means being in the form of a helicoidal passage co-axial to said axis, said helicoidal passage having a first end opening in said conduit and a second end opening into said first chamber.
 6. In a spraying nozzle as claimed in claim 1, said connecting means being formed of a passage forming the end of said inlet conduit and opening tangentially into said first chamber.
 7. In a spraying nozzle as claimed in claim 1, said inlet conduit being substantially co-axial to said axis and said nozzle further comprising an inner member co-axial to said axis and located within said first chamber, said first orifice, said second chamber and said second orifice; said inner member being formed with an axial through bore having a first end communicating with said inlet conduit and a second end arranged to receive the body of a second spraying nozzle disposed co-axially to the body of said first-named nozzle.
 8. A method for spraying a substance which consists: in imparting to said substance a perfect rotational motion about an axis; in causing the rotating substance to overflow axially through a first orifice concentric to said axis and thereafter through a second orifice also concentric to said axis and of larger diameter than said first orifice; and in guiding the rotating substance between the said orifices by a wall having a concave longitudinal profile, in such manner that in the vicinity of the first orifice the rotating substance may have a high angular velocity component with a reduced axial velocity component and that in the vicinity of the second orifice the said substance may have a reduced angular velocity component with a high axial component.
 9. A method as claimed in Claim 8, further comprising the step of guiding said rotating substance between said first and second orifice by a wall having an arcuate concave longitudinal profile, in such manner that in the vicinity of said first orifice said rotating substance may have a relatively high angular velocity component with a relatively reduced axial velocity component and that in the vicinity of said second orifice said substance may have a relatively reduced angular velocity component and a relatively high axial velocity component. 